Noop watchdog pretimeout governor, only an informational message is added to the kernel log buffer.
Signed-off-by: Vladimir Zapolskiy <[email protected]> --- Changes from v2 to v3: * temporarily removed tristate option, the governor can be built-in only Changes from v1 to v2: * removed #ifdef CONFIG_WATCHDOG_PRETIMEOUT_DEFAULT_GOV_NOOP, now this selection is done in a centralized manner, * added module owner reference to count users of the governor, * slightly improved description of the governors in Kconfig. drivers/watchdog/Kconfig | 11 ++++++++ drivers/watchdog/Makefile | 1 + drivers/watchdog/pretimeout_noop.c | 47 ++++++++++++++++++++++++++++++++++ drivers/watchdog/watchdog_pretimeout.h | 2 ++ 4 files changed, 61 insertions(+) create mode 100644 drivers/watchdog/pretimeout_noop.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index bf5938a..aee2eca 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1826,11 +1826,22 @@ config WATCHDOG_PRETIMEOUT_DEFAULT_GOV_PANIC a watchdog pretimeout event happens, consider that a watchdog feeder is dead and reboot is unavoidable. +config WATCHDOG_PRETIMEOUT_DEFAULT_GOV_NOOP + bool "noop" + select WATCHDOG_PRETIMEOUT_GOV_NOOP + help + Use noop watchdog pretimeout governor by default. If noop + governor is selected by a user, write a short message to + the kernel log buffer and don't do any system changes. + endchoice config WATCHDOG_PRETIMEOUT_GOV_PANIC bool +config WATCHDOG_PRETIMEOUT_GOV_NOOP + bool + endif # WATCHDOG_PRETIMEOUT_GOV endif # WATCHDOG diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 12df9c7..712f5bd 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -10,6 +10,7 @@ watchdog-objs += watchdog_core.o watchdog_dev.o watchdog-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV) += watchdog_pretimeout.o obj-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV_PANIC) += pretimeout_panic.o +obj-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV_NOOP) += pretimeout_noop.o # Only one watchdog can succeed. We probe the ISA/PCI/USB based # watchdog-cards first, then the architecture specific watchdog diff --git a/drivers/watchdog/pretimeout_noop.c b/drivers/watchdog/pretimeout_noop.c new file mode 100644 index 0000000..7ea8ed3 --- /dev/null +++ b/drivers/watchdog/pretimeout_noop.c @@ -0,0 +1,47 @@ +/* + * Copyright (C) 2015-2016 Mentor Graphics + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + */ + +#include <linux/module.h> +#include <linux/printk.h> +#include <linux/watchdog.h> + +#include <watchdog_pretimeout.h> + +/** + * pretimeout_noop - No operation on watchdog pretimeout event + * @wdd - watchdog_device + * + * This function prints a message about pretimeout to kernel log. + */ +static void pretimeout_noop(struct watchdog_device *wdd) +{ + pr_alert("watchdog pretimeout event\n"); +} + +static struct watchdog_governor watchdog_gov_noop = { + .name = "noop", + .pretimeout = pretimeout_noop, +}; + +static int __init watchdog_gov_noop_register(void) +{ + return watchdog_register_governor(&watchdog_gov_noop); +} + +static void __exit watchdog_gov_noop_unregister(void) +{ + watchdog_unregister_governor(&watchdog_gov_noop); +} +module_init(watchdog_gov_noop_register); +module_exit(watchdog_gov_noop_unregister); + +MODULE_AUTHOR("Vladimir Zapolskiy <[email protected]>"); +MODULE_DESCRIPTION("Panic watchdog pretimeout governor"); +MODULE_LICENSE("GPL"); diff --git a/drivers/watchdog/watchdog_pretimeout.h b/drivers/watchdog/watchdog_pretimeout.h index 8f2565e..86ddcbd 100644 --- a/drivers/watchdog/watchdog_pretimeout.h +++ b/drivers/watchdog/watchdog_pretimeout.h @@ -24,6 +24,8 @@ int watchdog_pretimeout_governor_name(struct watchdog_device *wdd, char *buf); #if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_DEFAULT_GOV_PANIC) #define WATCHDOG_PRETIMEOUT_DEFAULT_GOV "panic" +#elif IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_DEFAULT_GOV_NOOP) +#define WATCHDOG_PRETIMEOUT_DEFAULT_GOV "noop" #endif #else -- 2.5.0
